The herein application uses the human eye's lagging reaction to the visual stimuli, which in practical terms is determined to be approximately 1 ms for detecting a change and 24 ms for the brain to process the information. In reality the response to visual information takes approximately 100 ms, thus any event happening within that time frame remains invisible to the human eye, a phenomenon called scotoma. The light system described herein, uses this blind time to switch sequentially to other light sources thus illuminating the area of interest multiple times and at different angles. By applying this concept, the whole area is illuminated at constant intensity reveling accurate stereoscopic peripheral details exceeding by far the capabilities of any single source of illumination.
For the eye to perceive a continuous motion, a minimum of 30 video frames per second have to be shown, representing a frequency of approximately 30 Hz. This means that the same view angle has to be illuminated at 30 Hz frequency, and a complete switching of the multiple light sources of the system has to occur within the 33.3 ms time frame.
This represents a switching duration (period) Tn=8.33 ms per light source for a four light system or a period Tn=16.66 ms for two light sources. Accordingly for multiple number (n) of light sources, the switching time Tn is the full period T calculated for 30 Hz, divided by the number of sources, which in other words means an increase of the main oscillator frequency by the same factor, thus the total period Tn=T/n respectively corresponding to a frequency of fn=n 30 Hz at the main oscillator. The intensity of the light system is adjusted by changing the duty cycle which is the ratio between tON and period T of the device switching frequency T=tON+TOFF.
For the f=30 Hz frequency the period T is T=1/f=33.3 ms at one single light device, while a five lights system will have a period T5=T/5=6.66 ms, thus an oscillator frequency of f=151.5 Hz considering a duty cycle of 100% per lighting device.
The system may be assembled in a spherical dome configuration for complete 360 degrees (12.56 steradians) and be remotely controlled for special applications, in which case an increased number of light sources is required to cover a spherical dome. Accordingly, the main oscillator's frequency will be a multiple of the number of light sources used multiplied by 30 Hz. (ex. 8 sources=8×30 Hz=240 Hz min.)
The following elements of light radiation as perceived by the human eye are described below and are exploited by this system.                a) By understanding that the eye has a logarithmic response to brightness, a linear control of the source light intensity is inappropriate. For this purpose the PWM system proposed, has an Inverse Square Law response, where the intensity of the light I, is adjusted by a square of the previous value proportional to the linear increase of the distance to the object to be illuminated. This type of control will give the eye the perception of a constant illumination E factor, directly proportional to the intensity I and inversely to the distance d, to the object, without perceiving wide steps of intensity adjustment.        b) The square law operation E=I/d2, is achieved by using a logarithmic type of potentiometer in the PWM control circuit.                    Light Brightness is not the pursued property in this application, but rather in this example we seek a wide angle, stereoscopic view at lower luminosity for a panoramic view. The human eye has a wide range of brightness adjustment from 120,000 lux (full color spectrum) in full sun, 0.1 lux (with no color segregation) under moonlight. This application relies on the sacrificing of the high intensity illumination in exchange for the extension of the viewable area which requires no more than 50 to 200 lux for office activities with full color range identification. For instance, a very bright light source is useless and dangerous when exploring a wooded area at night which does not reveal immediate obstacles at foot or head level, or on the left and right sides. Instead, a much lower light source with lower contrast, illuminating the surroundings will reveal every obstacle from rocks on the pathway, to branches above the head and all the details in the bushes around, and gives a panoramic view of the scenery ahead. A smooth transition with low contrast variations of light covering a wide view angle is needed for a stereoscopic view. It is known that for a luminous intensity of 1-lux of illumination covering 1 m2, it takes 1-lm, or 1 Candela/str., or 1.46 mW/m2 of luminous flux in the best fit visible eye spectrum of a 555 nm wavelength of the color green. The source energy has to increase exponentially with the linear increase in distance, in order to maintain the same illumination of an object. By other interpretation, the luminous intensity I, per unit of surface area varies inversely proportional to the square of the distance d2 where, E is representing the light flux density in [lm/m]. This principle called the square law is used in the PWM control circuit.                        
For distant view applications a higher intensity spot light may be necessary, in which instance another such light source is added in the center of the dome.
The brightness of the system is directly dependant on the square law, where the electric current required to increase the luminous flux by 1 Cd/str. has to be increased by a factor of two. In case of a battery based system, the life of the battery is reduced by the same factor.
The switching control circuitry in this application, extends the battery life by having one single light source turned ON at a time, thus in principle, a multiple light source system will not consume a higher current than a single non-switched light device which is continuously in ON state. The power consumption of the light devices is increased proportionally if a longer ON time is chosen (as shown in timing diagram in FIG. 5).